“I played good, quite solid from the baseline and putting pressure on Petra. I was really, really solid, and I think this was really the key.”

Kvitova rued her subpar opening performance.

“Wasn’t the best start, but the good thing is there is still a chance to play better and to improve and maybe go somewhere forward,” she said.

Kvitova’s trademark firepower moved Svitolina around the hard court but the Ukrainian’s defence was up to the task.

A composed Svitolina made just four unforced errors in the opening set in a notable contrast to her error-riddled opponent, who struggled badly on serve and conceded the first set after her fifth double-fault.

Svitolina broke in the sixth game and held her nerve to claim just her second victory against Kvitova from nine meetings.

The Red Group action starts on Monday with number one seed Angelique Kerber playing Kiki Bertens and Naomi Osaka squaring off against Sloane Stephens in a battle of the past two US Open champions.